Opening device for thermoplastic bags

ABSTRACT

An opening and filling device for thermoplastic bags which comprises a nozzle connected to a source of gaseous fluid such as air, the nozzle having means to hang one or more bags thereon with the mouths of the bags just below the nozzle opening and having a deflecting baffle for deflecting air from the nozzle against the rear wall of the bag so that the gaseous fluid flows down between the rear wall and the front wall of the bag to open the bag. The nozzle is adapted to have a chute connected thereto with a gate for opening and closing the chute, said gate, when in open position, engaging the mouth of the bag to hold it totally in open position.

United States Patent Membrino Aug. 5, 1975 [54] OPENING DEVICE FORTHERMOPLASTIC 3,468,100 9/1969 Rube] 53/385 X BAGS 3.579.951 /1971Lowery 53/189 x 3,7l2,0l9 l/l973 Lamka et al..... 53/385 X [76]Inventor: Hercules Membrino, 1934 Arch St., 3 7, 22 4 1974 Kih e131, 53335 x Philadelphia, Pa. l9l03 [22] Filed: Mar. 6, 1974 PrimaryExaminerRobert L. Spruill [2 l] A I N 448 532 Arwmey, Agent, orFirmArthur A. Jacobs, Esq.

Related U.S. Application Data [63] fgys of Sept An opening and fillingdevice for thermoplastic bags which comprises a nozzle connected to asource of 52 us. (:1 53/189- 53/385 gaseous fluid Such as 0211c havingmeans 51 int. c1 1365b 43/36 hang one bags there with "mums [58] Fieldof Search 53/385. 189 bags Just helm "Mlle Opening and having a flectingbaffle for deflecting air from the nozzle [56] References Cited againstthe rear wall of the bag so that the gaseous fluid flows down betweenthe rear wall and the front UNITED STATES PATENTS wall of the bag toopen the bag. The nozzle is adapted 116003320 9/1926 Danqflgney 53/189 Xto have a chute connected thereto with a gate for :f t 5 3; opening andclosing the chute. said gate when in open 2376289 5,1945 222 8; 53/189position, engaging the mouth of the bag to hold it to- 2,629,369 2/19531 1615011 53/385 x Posmon 2160,70] 8/1956 Phelps 111111 53/189 X3,328.93; 7/1967 Harris et a1 3, 53/385 5 7 Drawmg guns I? 26 m 2g 24 aI A 20 I 78 OPENING DEVICE FOR THERMOPLASTIC BAGS This is acontinuation-in-part of co-pending application Ser. No. 395,542, filedSept. 10, 1973.

This invention relates to an apparatus for opening and fillingthermoplastic bags, and it particularly relates to an apparatus of theforegoing type which utilizes air pressure to open the bags prior tofilling.

As indicated in the aforesaid parent application, bags constructed ofthermoplastic material such as polyethylene, polypropylene, and thelike, are ordinarily difficult to open because the thermoplastic wallshave a great adherence to each other so that it is not only difficult toseparate the edges or lips of the walls defining the mouth of the bagbut also difficult to separate the walls themselves even when the lipshave been separated from each other.

The above difficulty was effectively solved by the apparatus describedin the aforementioned parent application where a pack of superimposedbags are clamped to the outer peripheral portion of a filling chute andwhere air is blown diagonally across the chute between the lips of eachsuccessive bag in such a manner that the air is blown over the front lipof the bag against the rear wall thereof and then passes downwardly intothe bag, thereby effectively opening the bag in linear arrangement withthe exit opening of the chute, whereby the opened bag receives fillingmaterial passing through the chute. This opening action is aided by thefact that the bags are clamped to the chute by a clamping plate or thelike which conforms to about half the circumference of the chute wherebythe bags are bent partially around the chute. This provides a lateralforce which causes the lip of the front wall to initially slightlyseparate from the rear wall to permit entrance of the air be tween thelips.

The above-described apparatus, although effective for its purpose,required the presence of the filling chute during the opening operation,whereby the air stream had to be delivered diagonally across the chutefrom front to rear. In order to obtain maximum effectiveness, it wasalso necessary to clamp the bags around half the periphery of the chute.

In accordance with the present invention, on the other hand the fillingchute is not required for the opening operation but may be used, ifrequired, as an auxiliary attachment. Furthermore, the air stream doesnot require a diagonal path from front to rear but may be directed alongthe rear surface so that lateral space is saved. In addition, the bagsneed not be clamped in semi-circular peripheral engagement with thechute in order to obtain effective entrance of the air into the nag.

i is, therefore, one object of the present invention to pro ILIF" athermoplastic bag opening apparatus which .m its function in a highlyeffective manner it i 'iresence of the filling chute and without annamicular peripheral engagement therewith.

A.iotl--. oziject of the present invention is to provide an apparain' ofthe aforesaid type wherein a chute is optionally provided and whereinsaid chute may be equipped with either a manually ormechanicallyoperated means to serve both as a stop means for filler n.itcrials passing through the chute and as an auxiliary arts formaintaining the lips of the bag in spaced opt tion during the fillingaction.

Another object of the present invention is to provide an apparatus ofthe aforesaid type which is extremely simple in construction,inexpensive to manufacture and easy to use.

Other objects and many of the attendant advantages of this inventionwill be readily appreciated as the same becomes better understood byreference to the following description when read in conjunction with theaccompanying drawings wherein:

FIG. 1 is a side view, partly broken away in section, of a bag openingdevice embodying the present invention.

FIG. 2 is an enlarged sectional view of a portion of the device of FIG.1 showing a chute assembly connected thereto.

FIG. 3 is a sectional view taken on line 3-3 of FIG. 2.

FIG. 4 is a fragmentary side view, partly in section and partly inelevation, showing a modification of the device of FIG. 2.

FIG. 5 is a fragmentary side sectional view showing another modifiedform of the device shown in FIG. 2.

FIG. 6 is a sectional view taken on line 6-6 of FIG. 5.

FIG. 7 is a front perspective view of a bag of the type utilized inconjunction with the present invention.

Referring now in greater detail to the various figures of the drawingswherein similar reference characters refer to similar parts, there isshown in FIG. I a bag opening de'vice, generally designated 10,comprising a housing 12 having an air inlet 14, a duct 16 connected tothe air inlet, and a blower (now shown) for drawing the air through theinlet 14 and blowing it through the duct 16 and through a two-pieceelbow conduit 18 to a housing or chamber 20. The housing 12 has aremovable cover plate 21 connected thereto by any desirable connectingmeans such as bolts, screws, clips or the like.

The housing or chamber 20 is arcuate in crosssectional shape (as bestseen in FIG. 3) and is provided with a flat wall 22. The upper end 24 ofthe housing 20 is closed and is provided with a stud 26 which extendsupwardly from the closed end 24. A washer 28 and nut 30 are provided onthe stud for the purpose of releasably clamping a lateral flange 32extending from a chute 34. The flange 32 is provided with a notch (notshown) which encircles the stud to permit inter-fitting of the flangewhen in clamped position.

The lower end 36 of the chamber 20 is open and is defined at the rear bythe arcuate wall 38 and at the front by the lower end of the flat wall22. Depending from the lower end of wall 22 is a baffle plate 40. Theplate 40 is rearwardly and downwardly curved.

Extending rearwardly from the wall 38 at the lower end of the chamber 20is a threaded stud 42 extending through an aperture in a plate 44 whichis itself connected at 46 to a bracket 48 pivotally mounted on a baseplate 50 extending forwardly from the housing 12. The stud 42 isprovided with a nut 52 which is adapted to bear against the plate 44.The stud 42 acts as a hanger for one or more thermoplastic bags 54 thatare each provided with a front wall 56 and a rear wall 58 (as best seenin FIG. 7. Each bag 54 has an open mouth defined by a front lip 60 and aperforated edge 62 defining the rear lip. The perforated edge 62 issomewhat higher than the front lip 60 and separates the rear wall of thebag from a selvage strip 64 having an aperture 66 to receive the stud42.

In operation, one or more bags, generally a pack of bags connectedtogether by their selvage strips 64, are hung on the stud 42, by firstremoving the nut 52, bending the plate 44 backwards off the bolt,inserting the bags onto the stud 42, bringing the plate 44 back onto thestud and thep applying the nut 52 to the stud and tightening it inplace. The blower (not shown) is then operated to blow a stream of airthrough the duct 18 into the chamber 20. The air passes through thechamber 20 and through the lower end 36. As it passes through lower end36, it is deflected by baffle plate 40 toward the rear wall of the frontbag 54. Since the lip 60 of the front wall of the bag is lower than theupper edge of the rear wall, the air stream passes along the rear wallbetween that rear wall and the front wall, thereby fully opening thebag, as shown in FIG. l. While the bag remains hanging and open, thefiller material may be inserted by hand or by any other means into thebag. After being filled, the bag is merely pulled away by tearing at theperforated edge 62. It may then be sealed or left open as desired forthe particular purpose.

In FIGS. 2 and 3 there is shown the same bag opening device as in FIG.1, the parts being referred to by the same reference characters, but inthese figures, the device has attached thereto the aforementioned chute34. The chute 34, as described above, is attached to the flat wall 22 ofthe chamber 20 by means of the flange 32 held in position by stud 26 andnut 30.

The chute 34 has an inclined wall 68 and is open at its upper and lowerends. The inclined wall 68 is provided with an aperture 70 in which ispivotally positioned an elbow portion 72 of a gate plate 74 which ispivotally movable against and away from the baffle plate 40 by means ofa handle 76 attached to a lever portion 78 on the outer side of theelbow portion 72. The lever portion 78 is biased toward the wall 68 by aspring 80 so that the gate 74 is normally in the closed position shownin FIG. 2. It is movable into the open position by pushing up on handle76. Although a biasing spring 80 is illustrated, it may be omitted,especially if it is desired to bias the gate into the open positionsince, in that case, the weight of the gate 74 would act as its ownbiasing means.

Thechute construction shown in FIGS. 2 and 3 has several functions: (a)it acts as a funnel for insertion of filling material into an openedbag, (b) it serves to meter the amount of filling material or preventpassage of such material when there is no opened bag in place, and (c)it serves as an auxiliary retention means whereby an auxiliary positiveforce is exerted to hold the mouth of the bag wide open during filling.The last two functions are provided by the gate 74 which, when in theclosed position, prevents passage of filling material through the chute,and, when in open position, not only permits sucn passage but abutsagainst the inner surface of the lip of the front wall of the bag (asshown in dotted outline in FIG. 2) to hold the mouth in wide openposition.

Automatic metering may be accomplished by connecting the handle 76 orthe gate 74 directly to a crank arm or the like (not shown) which isattached to an electric motor or the like actuated by a timing mechanism(not shown) or connected to a conveyor or the like (not shown) formovement in timed relationship therewith. Another manner ofautomatically actuating the gate is by means of a solenoid. This lattertype system is illustrated in FIG. 4 where the apparatus, gener allydesignated 90, is similar in all respects to that shown in FIGS. 1, 2and 3, including an air duct 92, a chamber 94 having a lower outlet end96, a stud 98 extending through a plate 100 for hanging bags 102, and anut I04 for holding the bags in place on the stud. The chute 106 issimilar to chute 34 except it is integrally connected to housing 94(although this is optional). A gate 108, similar to gate 74 is providedin the chute; however, the gate 108 is connected to the core 110 of asolenoid H2. The solenoid may be intermittently actuated by any desireddevice such as a conveyor or other feed mechanism.

FIGS. 5 and 6 illustrate a modified form of the invention and isgenerally designated 120. In this form, the chamber 122, similar tochamber 20, is integral with a cylindrical chute 124, being separatedtherefrom by a flat wall 126 having a baffle plate 128 at its lower end.

The baffle plate 128 is curved downwardly and rearwardly toward the rearwall of the outermost bag 130, the bags being hung on a stud 132 andheld by a nut 134 bearing against a plate 136 in similar fashion to thestructure shown in FIGS. 1-4. The lower outlet end of the chamber 122,indicated at 138, is situated above the baffle plate 128 in similarmanner to outlet end 36.

Attached to the chute 124 is a bracket 140 to which is hingedlyconnected, as by pin 142, a yoke 144. The yoke I44 is connected to agate plate 146. A lever handle 148 extends laterally from the gate 146.A spring encircles the pin I42 and is connected to the gate 146 to biasthe gate into closed position. When the handle 148 is pushed up (asshown in dotted outline FIG. 5), the gate 146 swings into the open,downward position (shown in dotted outline in FIG. 5), thereby acting inthe same manner and serving the same functions as gate 74.

The air stream for opening the bags may be continuous or, morepreferably, may be discontinuous or intermittent pulses dependent eitheron a separate standard timing mechanism (not shown) or on the actuationof a valve or pump motor by a conveyor or other feed means (not shown).

The chute may have either a round, rectangular or any other desirablecross-sectional shape, as is also true of the housing 122 and theductwork.

Although air has been described as the gaseous bag opening means, anyother desirable gas or vapor may be substituted when desired.

The invention claimed is:

I. A bag opening device comprising a chamber having an inlet for agaseous fluid and an outlet for said gaseous fluid, hanger meansadjacent said outlet for hanging thermoplastic bags in such a mannerthat the mouths of said bags, defined by a front wall and a rear wall,underlie said outlet, and a baffle plate depending from said chamber,said baffle plate constituting a continuation of one wall portion ofsaid outlet and underly' ing said outlet, said baffle plate being curvedin a manner to deflect the gaseous fluid from said outlet toward therear wall of a bag hanging from said hanger to open said bag, a chutepositioned adjacent said chamber, said chute having an inlet opening andan outlet opening, said outlet opening being adjacent said outlet fromsaid chamber, a gate positioned for pivotal movement within said chute,said gate being pivotally connected to one wall portion of said chuteand having one end thereof extending through said outlet opening of saidchute, said gate being pivotally movable from a chuteclosing position,wherein said gate is in an inclined position within said chute with thesaid one end engaging said baffle plate, to a full chute-openingposition, wherein said gate abuts against the interior surface of saidone wall portion of said chute with said one end underlying said onewall portion, said one end being of a length to overlie the mouth ofsaid bag when said gate is in said chute-closing position and to engagethe interior surface of the rear wall of said bag when said gate is insaid full chute-opening position, and a gateoperating means connected tosaid gate, said gatemeans is a solenoid actuating means.

i i i i I

1. A bag opening device comprising a chamber having an inlet for agaseous fluid and an outlet for said gaseous fluid, hanger meansadjacent said outlet for hanging thermoplastic bags in such a mannerthat the mouths of said bags, defined by a front wall and a rear wall,underlie said outlet, and a baffle plate depending from said chamber,said baffle plate constituting a continuation of one wall portion ofsaid outlet and underlying said outlet, said baffle plate being curvedin a manner to deflect the gaseous fluid from said outlet toward therear wall of a bag hanging from said hanger to open said bag, a chutepositioned adjacent said chamber, said chute having an inlet opening andan outlet opening, said outlet opening being adjacent said outlet fromsaid chamber, a gate positioned for pivotal movement within said chute,said gate being pivotally connected to one wall portion of said chuteand having one end thereof extending through said outlet opening of saidchute, said gate being pivotally movable from a chute-closing position,wherein said gate is in an inclined position within said chute with thesaid one end engaging said baffle plate, to a full chute-openingposition, wherein said gate abuts against the interior surface of saidone wall portion of said chute with said one end underlying said onewall portion, said one end being of a length to overlie the mouth ofsaid bag when said gate is in said chute-closing position and to engagethe interior surface of the rear wall of said bag when said gate is insaid full chute-opening position, and a gate-operating means connectedto said gate, said gateoperating means being positioned externally ofsaid chute and being operable to move said gate on its pivotalconnection.
 2. The device of claim 1 wherein said chute is separablefrom said chamber.
 3. The device of claim 1 wherein said chute isintegrAl with said chamber and is separated therefrom by a common wall.4. The device of claim 1 wherein said gate operating means is a handlefor manual operation of said gate means.
 5. The device of claim 1wherein said gate operating means is a solenoid actuating means.